Chapter 25 



Echinodermata Other than Holothuroidea 

 of Enewetak Atoll 



DENNIS M. DEVANEY (deceased) 



Bernice P. Bishop Museum 

 Honolulu. Hawaii 9681 7 



INTRODUCTION 



The echinoderm fauna at Enewetak became known 

 through publications by A. H. Clark (1952, 1954) that 

 recorded nonholothurian species from several of the 

 Marshall Islands. These two publications included nine 

 Asteroidea, nine Ophiuroidea, and 19 Echinoidea from 

 Enewetak. The Crinoidea and Holothuroidea were not 

 recorded from the atoll. 



In the late 1950s and early 1960s, Fred C. Ziesen- 

 henne, then with the Allan Hancock Foundation (AHF), 

 was asked by the Mid-Pacific Research Laboratory (MPRL) 

 to provide an identified reference collection of nonho- 

 lothurian echinoderms. His identifications, based on speci- 

 mens that he collected and those collected by students and 

 researchers working at MPRL, provided not only a valu- 

 able reference collection but also increased the number of 

 taxa known from Enewetak. An unpublished report, which 

 includes habitat information and keys to many of the 

 species, was prepared by F. C. Ziesenhenne and 

 R. A. Boolootian and was left at the laboratory for use by 

 visiting researchers. The holothurians were being studied 

 separately by Bertha Cutress, and her work has been 

 updated in a separate chapter for the present volume (see 

 Cutress and Rowe, Chapter 24). 



Since these early efforts, new studies and additional 

 records of echinoderms have been compiled by MPRL per- 

 sonnel and other researchers working at Enewetak. This 

 chapter brings together these numerous records (Table 1). 



Although the majority of Enewetak's shallow-water (to 

 about 100 m) echinoderms is reasonably well known, fauna 

 from deeper waters, especially in passes and off the sea- 

 ward reef face, is still incompletely known. Less than 1% 

 of the species so far recorded have been taken in water 

 deeper than 100 m. 



In comparison with the Marshall Islands as a whole, 

 knowledge of the Enewetak echinoderms is considerable. 



At this one atoll, 86% of all Marshall Islands species are 

 now known to occur at Enewetak. 



CRINOIDEA 



Although crinoids had been reported from the Marshall 

 Islands by Gislen (1940) and A. H. Clark (1952, 1954), no 

 species from Enewetak were included. Crinoids collected in 

 the late 1950s and identified by F. C. Ziesenhenne 

 included Comanthus bennetti and Comaster gracilis, species 

 recorded previously in the Marshall Islands from Rongelap 

 and Bikini by A. H. Clark (1952) and from Arno by A. H. 

 Clark (1954). Banner and Banner (1968) reported the 

 alpheid shrimp, Syna/p/ieus demani, from C. bennetti col- 

 lected at Enewetak. Zmarzly (jsersonal communication) 

 doubts the association of alpheids with this crinoid and, 

 based on her studies, feels that the host was a different 

 species. One of the Enewetak specimens of C. bennetti 

 examined by the author and Ann Fielding had a single 

 alpheid, S. stimpsoni, associated; two other alpheids were 

 also associated with other crinoid species at Enewetak 

 (Devaney and Bruce, Chapter 22, this volume). One of 

 these, S. carinatus, was also noted in association with "cri- 

 noids" at Enewetak by Banner and Banner (1968). Humes 

 (1972) reported a new species of copepod from C. ben- 

 netti, and Bartolini et al. (1973) examined pigments from 

 Enewetak specimens of this crinoid. 



In 1976, Devaney and Fielding examined Enewetak cri- 

 noids for their symbionts; crustaceans, polychaetes, myzos- 

 tomes, and other invertebrates were noted and collected. It 

 was thought that only Comanthus bennetti and Comaster 

 gracilis were represented in the material examined. Subse- 

 quently, however, due to a more intensive study on 

 Enewetak crinoid ecology and their symbionts by Zmarzly 

 in 1980, two additional species (Comanthina schlegeli and 

 Comanthus parvicirrus) were recognized among the 1976 

 material. The crustaceans associated with these crinoids 

 have been tabulated in the present volume (Devaney and 

 Bruce, pp. 225-226), and more information was given in 

 Zmarzly (1984), The small 10-armed antedonid, Dorometra 

 nana, was collected in 1976 off one of the southern wind- 

 ward islets (Ananij) beneath coral in limestone rubble at 18 



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